Device in a cable tie

ABSTRACT

The invention relates to a device in a cable tie. This comprises an elongate band part ( 2 ) of a certain width and thickness, which at one end has an elongate insertion part ( 2   a ) of a lesser width than the band part ( 2 ) and at its other end a locking head ( 3 ) with, on the one hand, a through-opening ( 4 ) for the band part ( 2 ), which has largely the same width as the band part ( 2 ) but a height greater than the thickness of the band part ( 2 ), and on the other a slit ( 5 ) in one transverse wall of the opening, the width of which slit is such that it will allow the insertion part ( 2   a ) to be inserted into the opening ( 4 ) via the slit ( 5 ), forming a band loop. A tongue ( 6 ), which is designed to lock the band part ( 2 ) in relation to the locking head ( 3 ), extends from one end of the opening ( 4 ) to the other and towards the slit ( 5 ). A sheet-metal insert ( 7 ) reinforcing the locking head ( 3 ) is embedded in the locking head ( 3 ).

The present invention relates to a device according to the pre-characterising clause of claim 1.

Such a cable tie has been previously disclosed, for example, by SE 9903378-9.

An advantage with cable ties of this type is that a tie loop can be quickly and readily produced by introducing the narrowing section of the band part into the through-opening via the slit in the locking head. A disadvantage with such a locking head provided with a slit, often termed an open locking head, is that the force at which the head is no longer capable of holding the band part is determined by the wall thickness of the locking head and the prevailing temperature; since cable ties of this type are made from a plastic material, limits must inevitably be placed on the temperatures below which the cable ties can be used without the risk of the cable tie losing its ability to hold together.

In order to increase the force that is required in order to break open a cable tie SE 9903378-9 C2 discloses how peg-shaped projections, pointing in towards the through-opening in the locking head, can be made to engage with corresponding grooves running along each edge of the band part.

The object of the present invention is to provide a cable tie that improves upon the cable tie of the aforementioned type. This is achieved by the distinguishing features specified in the characterising part of claim 1.

The invention will be described in more detail below with reference to the drawing attached in which embodiments of a cable tie according to the invention are shown in schematic form. More specifically,

FIG. 1 shows a plan view of a first embodiment of a cable tie, FIG. 1 a is a detailed view of the locking head of the cable tie and FIG. 1 b is a detailed view corresponding to that in FIG. 1 a but with the band part of the cable tie inserted into the locking head.

FIGS. 2 and 2 a respectively show a sectional plan view and a perspective, partially sectional view of a locking head with the locking tongue of the cable tie integrally formed with a sheet-metal insert according to the invention. FIG. 2 b shows an example of a blank for a sheet-metal insert according to the invention and FIG. 2 c shows a perspective view of the blank according to FIG. 2 b designed for interaction with an open lock housing.

FIG. 3 shows a plan view of an alternative embodiment of a cable tie having an insert according to the invention and FIG. 3 a is a detailed view of the locking head of the cable tie shown in FIG. 3 with band part inserted therein.

The cable tie in FIG. 1, which is generally denoted by 1, comprises an elongate band part 2 of a certain width and thickness. At one end the band part 2 has an insertion part 2 a of a lesser width than the band part 2. The insertion part 2 a terminates in a grip tab 2 a 1. At its other end the band part 2 has a locking head 3 with, on the one hand, a through-opening 4 for the band part 2, and, on the other hand, a slit 5 in one transverse wall of the opening 4. The opening 4 has substantially the same width as the band part 2 and a height greater than the thickness of the band part 2. The width of the slit 5 is such that it will allow the insertion part 2 a to be inserted into the opening 4 via the slit 5, forming a band loop. In the locking head 3, or more specifically in the opening 4, there is a locking tongue 6, which extends towards the slit 5 diagonally in the opening 4 from one end thereof. The tongue 6 is designed to fix the band part 2 in relation to the locking head when the band part is inserted into the through-opening 4.

According to the invention a sheet-metal insert 7, preferably of stainless steel sheet, is embedded in the locking head 3, the function of the insert being to make the locking head 3 less susceptible to forces inclined to expand the slit 5 with the result that the band part 2 risks disengagement from the tongue 6. In the embodiment shown in FIGS. 1, 1 a, 1 b this is integrally formed with the locking head 3 and preferably has grooves, known in the art and designed to interact with corresponding grooves on the band part 2. The insert 7 is congruent with the through-opening 4 in the locking head 3. The insert 7 is preferably embedded in such a way that the inner sides thereof are covered by the material of which the locking head 3 is made, but in an alternative embodiment the insert 7 is embedded so that its inner surfaces are exposed.

The embodiment according to FIG. 2, as will be apparent from a separate characteristic of the invention, has a tongue 6 integrally formed with the insert 7. With such a sheet-metal tongue the grooves on the band part 2 can be omitted or at least simplified without this resulting in an inferior engagement between the tongue 6′ and the band part, which in turn means a simpler manufacturing process and a cheaper cable tie.

Referring to FIGS. 2 b and 2 c, an example will now be described of how the insert 7 according to the invention is manufactured, whilst FIG. 2 a illustrates how the insert 7 is inserted into the locking head 3. Starting from a punched-out sheet-metal blank according to FIG. 2 b, bending operations are carried out in stages along dotted lines, so that the insert shown in FIG. 2 a is obtained. The person skilled in the art will appreciate that the punching and bending operations can be performed in a series production tool and can consequently be automated, making it highly cost-effective. The insert 7 is introduced into the locking head in conjunction with the manufacture of the cable ties, which is done by injection moulding.

The insert 7, as will be seen from FIG. 2 a is well anchored in the locking head 3 and it must be noted in particular that there is a section 3 a for the tongue 6′, which is designed to support the tongue 6 when tightening and locking the band part 2. This section 3 a, however, is of no crucial importance for the locking function of the tongue 6.

In the embodiment of a cable tie according to the invention shown in FIGS. 3 and 3 a, the locking head and the insert have flanges 3 b and 7 a, respectively, which extend along the edge of the slit 5 pointing in towards the through-opening 4. These flanges 3 b, 7 a are designed, when the band part 2 is inserted into the opening 4, to interact with corresponding grooves 2 b, in order to further increase the capacity of the locking head 3 to cope with stresses without the slit 5 being expanded with the risk that the engagement between the band part 2 and the locking head 3 will be lost.

It will be appreciated that the embodiment with the flanges 3 b, 7 a shown in FIGS. 3, 3 a may have a tongue 6 integrally formed with the locking head, that is to say made of plastic, or integrally formed with the insert 7, that is to say made of sheet metal.

In an alternative embodiment the flanges 3 b are omitted, so that the engagement in the grooves 2 b is maintained solely by the flanges 7 a integrally formed with the insert 7.

In another alternative embodiment the flanges 7 a are omitted so that the engagement in the grooves 2 b is maintained solely by the flanges 3 b. 

1. Device in a cable tie comprising an elongate band part of a certain width and thickness, which at one end has an elongate insertion part of a lesser width than the band part and at its other end a locking head with, on the one hand, a through-opening for the band part which has substantially the same width as the band part but a height greater than the thickness of the band part, and, on the other hand, a slit in one transverse wall of the opening, the width of which slit is such that it will allow the insertion part to be inserted into the opening via the slit, forming a band loop, a tongue, which is designed to lock the band part in relation to the locking head extending from one end of the opening to the other and towards the slit, wherein a sheet-metal insert reinforcing the locking head is embedded in the locking head.
 2. Device according to claim 1, wherein the insert is congruent with the opening in the locking head.
 3. Device according to claim 1, wherein the tongue is integrally formed with the insert.
 4. Device according to claim 1, wherein the locking head, in a manner known in the art, has flanges extending along edges of the slit and in towards the through-opening, the flanges being designed to interact with corresponding grooves in the band part.
 5. Device according to claim 4, wherein the insert is formed with corresponding metal flanges reinforcing the flanges of the locking head and interacting with grooves in the band part.
 6. Device according to claim 1, wherein the insert has flanges extending along edges of the slit and in towards the through-opening, the flanges being designed to interact with corresponding grooves in the band parts.
 7. Device according to claim 2, wherein the tongue is integrally formed with the insert.
 8. Device according to claim 2, wherein the locking head, in a manner known in the art, has flanges extending along edges of the slit and in towards the through-opening, the flanges being designed to interact with corresponding grooves in the band part.
 9. Device according to claim 2, wherein the insert has flanges extending along edges of the slit and in towards the through-opening, the flanges being designed to interact with corresponding grooves in the band part. 